I was wondering if someone can explain the technical and specific differences between a “Dutch Chamber” and a “NATO Chamber” in 5.56mm?
TIA.
Supposedly, a ‘Dutch’ chamber is meant to increase reliability. It’s similar to a ‘Wylde’ chamber, which essentially allows you to shoot both 5.56mm and .223 Rem.
I would suspect that Wylde and Dutch are very close dimensionally, however, I don’t have the specs to support that statement. 
Thanks. I did an Internet search and could not come up with anything that specifically describes it.
Here is an explanation I received this (redacted to mitigate any flames should certain individuals on this board find out who posted it):
It is called a dutch chamber because when the Dutch adopted the C7 and C8 rifle from Diemaco, the C8’s were plagued with functional issues and Diemaco had to come up with a solution or loose the entire contract.
They looked at a number of solutions and came up with a slight adjustment of the chamber dimensions. It is not really loose or tight. It has a generous freebore, slight difference in angle at the throat. All to optimize reliability. The ass end of the chamber is also slightly more generous.
[SNIP]
The chamber is a NATO 5.56mm chamber and all 5.56 headspace gauges are appropriate. The HK 416 uses a different chamber, but is similar to a dutch chamber.
BTW, the Diemaco C8 SFW has been adopted by many tier 1 ct units because in comparative testing it is much more reliable than the M4. In the SAS trials, more reliable than the Sig 550. This is attributed to the chamber.
Why were the Dutch having problems with standard 5.56mm chambers?
Tilting at windmills?
<ba-dump ching>
i was thinking that there are too many dykes.
Wow, eight posts and not one Dutch Oven crack.
I thought the Wylde chamber was kind of like a tight 556 chamber for max accuracy, while it sounds like the Dutch chamber is pure function and reliability?
That’s the impression I got.
I wonder if it had anything to do with the fact that a big chunk of their land mass is reclaimed? I remember reading that during Operation Market-Garden a lot of radios could not achieve their operational max range because of all the water logged areas.
I’ve heard of rounds swelling in the chamber of a firearm during the Vietnam War. It could be the Dutch were experiencing the same issues.
Then again, this is just a guess on my part and I could be full of crap.
Do they use standard SS109 bullets with brass casing?
Maybe they use steel casing?
Seems odd that the rest of the world is getting along fine with standard 5.56mm but they need something different.
My Father-In-Law calls them Arrogant Germans.
I have never heard of a Dutch Chamber.
Just my .02,
LeonCarr